Maybe try some other types of letter formations if she is interested in writing/letter. Try making them out of playdough or writing them in a sand tray or rice or flour, writing them on the shower screen in coloured water - try and make it fun. Go outside and make a letter out of flowers and leaves they collect or go to the beach and write messages in the sand.

Is she interested in writing cause she has seen you do it - what about letting her use texta over the top of a letter you write to her like decoding a message and then you can read it to her

PS - we posted at the same time. You will probably find she will be fine at school, I find (as a teacher and a parent) most kids give their parents a much harder time than the teacher. It's great that she wants to learn - but you might find that she's not interested so much in "writing" like we do it as she is in understanding how writing works - sending messages and decoding what the letters mean and say??? Does that make sense?